Video Transcript
Round 2767545 to the nearest ten.
We’re given a fairly long number to look at in this question. It has seven digits. We read the number as 2767545. And we’re asked to round this number to the nearest ten. At the moment, that tens digit in this number is four. The number ends with 45. We can use a number line to think about the two multiples of 10 either side of this long number. Our number comes somewhere in between 2767540 and 2767550. Now if we look at the last two digits in our number, we can see that it ends in 45. Now 45 is exactly halfway between 40 and 50. So we can mark this on our number line, halfway along.
Now how should we round our number? Should we round it down to the nearest ten or up to the nearest ten? When we have a number that’s exactly halfway, what do we do? Well, we’re told we need to round to the nearest ten. So that’s this digit here. But the digit that tells us whether to round up or down is the next number along to the right. It’s the digit five. This is the digit we need to be looking at.
We know that when a number ends in one, two, three, or four, we round down. And when a number ends in five, six, seven, eight, or even nine, we round up. And we can see that our digit is a five. So we know from this rule that we need to round the number up to the nearest ten. The five becomes a zero and the tens digit goes up to the next ten. Even though it’s halfway between two multiples of 10, we need to round our number up.
You know, sometimes we can look at large numbers like this one — and this one has seven digits — and think to ourselves, “This is gonna be a tricky question. How am I going to deal with a number that includes millions, hundreds of thousands and so on?” But because we’ve been asked around to the nearest ten, we’ve only really needed to look at the tens digit and the digit to the right of it, which is the ones digit.
Look at the number line. Can you see the digits that we’ve written in orange? What we’ve done here is exactly the same as rounding 45 up to 50. There’s no difference whatsoever. And so if we round to 2767545 to the nearest ten, it becomes 2767550.
